I think it's kind of ambiguous what a park flier is. What I take it to mean is any plane that can be flown safely in an average park - say the size of a couple of football fields. I've seen some 60" or so planes being flown in "Parkflyer Territory" and didn't think they were a problem.

The AMA gives a speed and weight definition of a Park Flyer. I think of Sport Flying as more of a style of flying as is 3D, pattern, combat and indoor. Many planes can be Park Flyers and can fly in various styles. To me a Sport Flyer would indicate more acrobatic capabilities than a trainer.

Thanks for the replys, so essentially then when a radio mfg refers to their recvr as a park flyer compatable it is not so much an issue of range, as size and weight?

Ah. Good question. I've wondered the same thing myself. Does it mean reduced range (compared to what??) or reduced size/weight or what? Or does it mean, "don't use this receiver on your 30 pound, 120 inch wingspan model?"

A "sport flier" is usually a plane of whatever size that is reasonably easy to fly without extensive experience.

The official AMA definition of a "Park Flyer" is an electric plane 2lbs or less and speed less than 60mph. Generally manufacturers of this size plane assume the radio systems do not need the greater range needed for larger planes. A rule of thumb is that if it is too far away to see orientation and you bash it, you will still have radio control.

The popularity of smaller electric planes that can be flown in local parks or similar locations without bothering other people is increasing rapidly. The AMA Park Flyer division is working hard to develop standards and education to promote fun for RC pilots, maintaining places for everyone to fly and insuring the safety of everyone.

It's best to join the Academy of Model Aeronautics for a number of reasons including liability. The specific Park Flyer membership costs about half what full AMA membership costs, and is intended for guys who fly in ordinary city parks or other local areas not designated as AMA club fields.

what are the differances or what actually defines the definition of a Park flyer

And what is or defines a sport flyer from say anyother types

My interpretation: Park Flyers are usually small, light wt.;foamies, that can be flown safely in a more restricted location / such as a park. Being small etc. they do not safely fly at long range therefore, the park flyer restricted range RX's. Sport flyers generally refers to aircraft built up of lite ply/balsa and may be powered by electric or glow fuel. Far larger, faster and heavier than a park flyer therefore require much more space for safe operation. They are similar in construction to the more advanced pattern type and giant scale but without the more advanced necessitys of those type. Can be used as trainers, in some cases or overall fun fly aircraft. Many have reasonable aerobatic capabilities.

My interpretation: Park Flyers are usually small, light wt.;foamies, that can be flown safely in a more restricted location / such as a park. Being small etc. they do not safely fly at long range therefore, the park flyer restricted range RX's. Sport flyers generally refers to aircraft built up of lite ply/balsa and may be powered by electric or glow fuel. Far larger, faster and heavier than a park flyer therefore require much more space for safe operation. They are similar in construction to the more advanced pattern type and giant scale but without the more advanced necessitys of those type. Can be used as trainers, in some cases or overall fun fly aircraft. Many have reasonable aerobatic capabilities.

Not true at all. Parkflyers can be made of balsa OR foam, not just foam. For example, the MUS, or a Mountain Models Switchback.

IMO, there is no difference between a parkflyer or a sport flyer- I can make both do both. I can take a 72" .40 glow plane look like a parkflyer, and comfortably fly it in a fairly large park. Now, that's not the brightest idea, however it can be done. I can make that same model sport fly.

Short range and long range receivers can be used in either type of model, although many micro receivers nowadays made for parkflyers do have full range, such as the Berg 4, or a Hitec Micro 05S. I myself use only full range receivers, because they don't cost a whole lot more than a short range receiver, nor do they weight much more either